Preprints
https://doi.org/10.5194/essd-2022-34
https://doi.org/10.5194/essd-2022-34
 
04 Feb 2022
04 Feb 2022
Status: a revised version of this preprint was accepted for the journal ESSD and is expected to appear here in due course.

The CISE-LOCEAN sea water isotopic database (1998–2021)

Gilles Reverdin1, Claire Waelbroeck1, Catherine Pierre1, Camille Akhoudas1, Giovanni Aloisi2, Marion Benetti1, Bernard Bourlès3, Magnus Danielsen4, Jérôme Demange1, Denis Diverrès3, Jean-Claude Gascard1, Marie-Noëlle Houssais1, Hervé Le Goff1, Pascale Lherminier5, Claire Lo Monaco1, Herlé Mercier5, Nicolas Metzl1, Simon Morisset6, Aïcha Naamar1, Thierry Reynaud5, Jean-Baptiste Sallée1, Virginie Thierry5, Susan E. Hartman7, Edward M. Mawji7, Solveig Olafsdottir4, Torsten Kanzow8, Antje Voelker9,10, and Igor Yashayaev11 Gilles Reverdin et al.
  • 1Sorbonne University, LOCEAN - IPSL, CNRS–IRD–MNHN, Paris, France
  • 2Université de Paris, Institut de Physique du Globe de Paris, CNRS, 75005 Paris, France
  • 3UMS IMAGO, IRD, Plouzané, France
  • 4Marine and Fresh Water Institute, Iceland
  • 5University of Brest, LOPS, IUEM, UBO–CNRS–IRD–Ifremer, Plouzané, France
  • 6Amundsen Science, Québec, Canada
  • 7National Oceanogaphy Center, Southampton, UK
  • 8MARUM/Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany
  • 9Instituto Português do Mar e da Atmosfera, Lisbon, Portugal
  • 10Centro de Ciencias do Mar, Faro, Portugal
  • 11Bedford Institute of Oceanogaphy, Dartmouth, Nova Scotia Canada

Abstract. The characteristics of the CISE-LOCEAN sea water isotope data set (δ18O, δ2H, later designed as δD) are presented. This data set covers the time period from 1998 to 2021 and currently includes close to 8000 data entries, all with δ18O, three quarters of them also with δD, associated with a time and space stamp and usually a salinity measurement. Until 2010, samples were analysed by isotopic ratio mass spectrometry, and since then mostly by cavity ring-down spectroscopy (CRDS). Instrumental uncertainty on individual data in this dataset is usually with a standard deviation as low as 0.03 / 0.15 ‰ for δ18O and δD. An additional uncertainty is related to uncertain isotopic composition of the in-house standards that are used to convert daily data into the VSMOW scale. Different comparisons suggest that since 2010 the latter have remained within at most 0.03 / 0.20 ‰ for δ18O and δD. Therefore, combining the two suggests a standard deviation of at most 0.05 / 0.25 ‰ for δ18O / δD.

Finally, for some samples, we find that there has been evaporation during collection and storage, requiring adjustment of the isotopic data produced by CRDS, based on d-excess. This adds an uncertainty on the adjusted data of roughly 0.05 / 0.10 ‰ on δ18O and δD. This issue of conservation of samples is certainly a strong source of quality loss for parts of the database, and ‘small’ effects may have remained undetected.

The internal consistency of the database can be tested for subsets of the dataset, when time series can be obtained (such as in the southern Indian Ocean or North Atlantic subpolar gyre). These comparisons suggest that the overall uncertainty of the spatially (for a cruise) or temporally (over a year) averaged data is on the order of or less than 0.03 / 0.15 ‰ for δ18O / δD. On the other hand, 17 comparisons with duplicate sea water data analysed in other laboratories or with other data sets in deep regions suggest a larger scatter. When averaging the 17 comparisons done for δ18O, we find a difference close to the adjustment applied at LOCEAN to convert salty water data from the activity to the concentration scale. Such a difference is expected, but the scatter found suggests that care is needed when merging datasets from different laboratories. Examples of time series in the surface North Atlantic subpolar gyre illustrate the temporal changes in water isotope composition that can be detected with a carefully validated dataset.

Gilles Reverdin et al.

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on essd-2022-34', Anonymous Referee #1, 07 Apr 2022
  • RC2: 'Comment on essd-2022-34', Anonymous Referee #2, 19 Apr 2022
  • AC1: 'Comment on essd-2022-34', Gilles Reverdin, 02 May 2022

Status: closed

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on essd-2022-34', Anonymous Referee #1, 07 Apr 2022
  • RC2: 'Comment on essd-2022-34', Anonymous Referee #2, 19 Apr 2022
  • AC1: 'Comment on essd-2022-34', Gilles Reverdin, 02 May 2022

Gilles Reverdin et al.

Data sets

Water isotopes of sea water analyzed since 1998 at 741 LOCEAN Waterisotopes-CISE-LOCEAN https://doi.org/10.17882/71186

Gilles Reverdin et al.

Viewed

Total article views: 425 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
311 97 17 425 10 10
  • HTML: 311
  • PDF: 97
  • XML: 17
  • Total: 425
  • BibTeX: 10
  • EndNote: 10
Views and downloads (calculated since 04 Feb 2022)
Cumulative views and downloads (calculated since 04 Feb 2022)

Viewed (geographical distribution)

Total article views: 395 (including HTML, PDF, and XML) Thereof 395 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 24 May 2022
Download
Short summary
The CISE-LOCEAN sea water stable isotope data set has close to 8000 data entries. The δ18O and δD isotopic data measured at LOCEAN have uncertainties of at most 0.05 / 0.25 ‰. Some data were adjusted to correct for evaporation. The internal consistency is explored indicating that the data can be used to investigate time and space variability to within 0.03 / 0.15 in δ18O / δD . 17 comparisons with data analyzed in other institutions suggests larger differences with other data sets.